Unformatted text preview: Agriculture: Terms Agriculture “Agriculture is the deliberate
modification of the Earth’s surface
through cultivation of plants and
rearing of animals to obtain
sustenance or economic gain.”
“Cultivate” means “to care for.”
Any cultivated plant is called a
crop. Origins of Agriculture
Subsistence & Commercial Agriculture
Economic & Cultural Issues 1 2 Hunters & Gatherers The Pre-Agricultural World About 0.005% of
humanity today live
Based on what we
know about them,
and on archaeological
evidence, we can
what most people did
before agriculture: Human beings – or something very
like human beings – have been
around for at least two million years.
But we’ve only been practicing
agriculture for something like 10,00020,000 years.
Before agriculture there was what we
call hunting and gathering. Small groups (less than 50
people), low population density.
Gathering is usually much more
important than hunting (usually
60% to 80% of the food).
In most societies men hunt and
fish, and women gather.
Getting food usually takes no more
than 10% of people’s time.
Politics are informal, consensus
based; little social stratification;
beliefs are animistic.
Limited material culture; no
Strong ties to land, but nomadic
and mobile. 3 Origins of Agriculture 4 What is “domestication?” We can never know where agriculture
began – it began in prehistory, and it
probably began in more than one place.
However, historians, archaeologists,
agronomists, geographers and other
scholars have worked for over a century
now trying to determine just where the
processes that lead to agriculture – and
to civilization – began. Some of the changes that take place when
plants are domesticated:
– Gigantism (bigger seeds or fruits)
– Loss of seed dispersal mechanisms
– Loss of bitter or toxic substances
– Changes in floral structures or pollination schemes
– Changes in flowering cycle
– Diversity of form
– Loss of mechanisms to protect against predators 5 Information source: http://hcs.osu.edu/hcs200/Notes1.htm 6 1 Origins of Agriculture
Carl Sauer’s theory:
– Not in response to
– Not among nomads.
– Not in grasslands or river
– In places of high
– In places of high plant
– Beginning with
not grains. ∴ SE Asia
14,000-35,000 BP First Vegetative Planting More conventional theory: According to Sauer, the
agriculture appeared in
Southeast Asia, and
probably involved root
vegetables like taro and
yams, and perhaps tree
crops like bananas.
throughout Asia and
eventually to the Near
East and Europe.
took place in Africa (oil
palm, yam) and South
arrowroot). – As a consequence of
gathering seeds, gatherers
noted which plants produced
best, and began (perhaps
accidentally) to care for
– Agriculture began with crops
like grains, lentils and
– Agriculture began in the
river valleys – the Tigris &
Euphrates, the Nile, the
Indus, the Huang He, and
the high valleys of Mexico
and Peru. ∴ Near East
7 8 First Seed-Based Agriculture Origins: Vegetative Hearths Seed-based
agriculture began in
at least three places
according to Sauer:
– Western India
– Northern China
– Ethiopia It diffused quickly
from India to the
Near East, then to
9 Origins: Seed-Based Hearths 10 Origins of Selected Crops 11 12 2 Subsistence vs. Commercial
vs. Contrasting Theories
Your book doesn’t mention them, but at least
two other people should be included here: Subsistence and commercial
agriculture differ in five ways: – Nikolai I. Vavilov (1887-1943)
Looked for “centers of diversity,” which he believed were
also “centers of domestication.”
Collected more than 250,000 seed samples; identified 8
agricultural hearths: Southeast Asia; China; India; TurkeyIran; Mediterranean; Ethiopia; Mexico/Central America;
Andes/Brazil/Paraguay. – Jack R. Harlan (1917-1998)
Agronomist and geneticist; actually met Vavilov at a
meeting in Washington in 1932.
– Three "centers": the Near East, Northern China, and
– Three “non-centers”: S.E. Asia, S. America, and Africa
13 Labor Force In Agriculture – PURPOSE
(consumption vs. off-farm sales)
– PERCENTAGE OF FARMERS
(majority vs. minority of population)
(mostly hand vs. mostly mechanized)
– FARM SIZE
(small vs. large)
– FARMS AND OTHER INDUSTRIES
(mostly isolated vs. highly integrated) 14 Tractors per 1,000 15 Agricultural Regions
of the World 16 Climate & Agriculture Regions
identical. 17 18 3 Subsistence Agriculture:
Also known as “slash and
Most common today in
tropical areas (adaptation
to poor soils).
Small-scale, no machines.
Temporary – short
occupation, long fallow
Crops vary from region to
Only 5% of the world’s
shifting cultivation. Slash & Burn:
Effects 1986 1992 Farmers clear land
and burn the debris.
Poor soils can only
support crops for
two-three years. Source: http://science.nasa.gov/headlines/y2003/16may_biocorridors.htm 19 Subsistence Agriculture:
Based on herding
Adapted to dry climates
where other types of
agriculture are basically
Mostly in North Africa,
Near East and Central Asia
Choice of animals varies –
dromedary camels, sheep
and goats in North Africa
and Arabia, bactrian
camels and horses in
Central Asia, etc. 1975 Subsistence Agriculture:
Intensive, Wet Rice Dominant
areas of high
population density – East,
Extremely small farms, worked
by hand (few machines),
focused on rice.
Rice is unique: it can grow in
water (well, in flooded fields).
Flooded fields have many
advantages: pest control, easy
fertilizing, fish production.
Where climate is favorable,
farmers can double crop –
raise more than one crop
per field per year. Nomads don’t just
“wander” – precise
strong sense of territory.
Some nomads practice
seasonal migration up
and down mountains. Source: http://www.loc.gov/exhibits/empire/ethnic.html Sources: http://encarta.msn.com/media_461550731_761582457_-1_1/Satellite_Images_of_Deforestation.html;
20 21 Subsistence Agriculture:
Intensive, Wet Rice Not Dominant Wet rice (“paddy” or
“sawah” grown) cultivation
– Rice seed is planted in a
nursery, and raised until
ready to be transplanted.
– Fields are prepared and
– Fields are flooded.
– Individual seedlings are
planted, individually, by
hand, in the field.
– Each plant is cared for
harvested, by hand, with
special knives. Source: http://pubs.usgs.gov/publications/text/tectonics.html 22 European Crop Rotation This is a very ancient form of agriculture – think of
places like Medieval Europe, or rural Latin America,
as well as more arid parts of South and East Asia.
Widely practiced in areas where climate doesn’t
support wet rice.
Similar in many ways to areas
where wet rice dominates, but
emphasizes different crops
(wheat, barley, corn, etc.).
In these areas farmers practice
crop rotation to increase yields
and maintain the health and
fertility of their farms.
Source: http://www.pfpcanada.com/research.htm 23 24 4 Commercial Agriculture:
Mixed Crop & Livestock Farming
chickens etc.) and
Most crops raised
are fed to animals.
Most land is
devoted to crops.
Most money is
animals and animal
products. Commercial Agriculture:
Dairy products (butter,
cheese, etc.) are
Mostly produced in
Western Europe, North
Australia and New
Because milk is
near markets – in the
– Livestock supply manure
to fertilize the crops.
– Workload can be more
throughout the year.
– Less seasonal variation
in income. Source: http://www.epa.gov/esd/land-sci/trends/eco64/eco64_samp57.htm 25 Today, transportation
makes it possible for milk
producers to locate
hundreds of miles from
However, the further from
markets, the less likely
dairy operations are to
produce fluid milk. Source: http://clinton.senate.gov/issues_agriculture.html 26 Commercial Agriculture:
Grain Farming US Dairy Production, by Region Grains – wheat, corn, oats, barley, rice, etc. – are
Globally, the most important crop grown is wheat – more
wheat is exchanged in international commerce than any
other grain (most rice is consumed where it is produced).
Wheat is usually produced in areas where it is too dry for
The US is the largest grain producing region on earth.
– Winter wheat region (wheat planted in fall, dormant
through winter, grows and is harvested in late
spring or summer).
– Spring wheat region (wheat planted in spring,
harvested in late summer).
– Other wheat regions (Eastern Washington)
Other major producers include Canada, Argentina,
Australia, France and the UK.
Large scale production only became possible in the 19th
century, with the development of mechanized agriculture.
Source: http://thesocietypages.org/graphicsociology/tag/agriculture/ 27 Commercial Agriculture:
Adapted to the
region – warm dry
summers, mild wet
winters (this is a very odd
pattern – most places get
plenty of precipitation in
Most crops grown for
human consumption – not
Primary source of the
world's olives, grapes, etc. 28 Commercial Agriculture:
Ranching is, in some ways, the
commercial version of pastoral
Ranching is a type of commercial
agriculture adapted to areas which are
too dry for other forms of agriculture.
Ranching is not as profitable per acre
as farming – if irrigation makes
farming possible, ranching usually
ends. Wheat and other grains are
also grown in traditional
Mediterranean areas (but
mostly for local
Animals and animal
products of less importance
(at least traditionally).
Source: http://www.usaid.gov/wbg/asalah.htm Source: http://water.usgs.gov/pubs/circ/circ1225/html/cover.html 29 30 5 US Cattle Ranching Ranching Today
Some cattle are still
raised on ranches, but
most are on shifting
Many cattle are now
shipped to feed lots for
fattening near their
Ranching is also
practiced in other
developed countries: Cattle ranching in the US begins with
Columbus's second voyage.
– Cattle ranching was small scale on the East
Coast in the 16th to 18th centuries.
– Rapidly expanding cities became major
markets for beef.
– In the Western US, semiarid areas could
be used to produce beef cattle – the
problem was getting the beef to market.
– The solution – long-distance cattle drives,
from rural areas to the nearest railroad.
– By the end of the 19th century, cattle
drives were basically over. – Spain and Portugal.
– Argentina, Brazil,
– Australia. End of open range.
Expansion of railroads.
Changes in cattle breeding.
Cattle ranching changed to mostly fixed
Source: http://www.ndsu.nodak.edu/instruct/isern/431/cattle.htm 31 Commercial Agriculture:
(or “Truck Farming”)
Farming” Truck farming has nothing
to do with trucks or
trucking! The word "truck"
comes from an old English
word meaning "to carry" or
Specialty fruit and
vegetable farming – very
similar to "market
Fresh fruits and vegetables
– perishable produce.
Farmers tend to specialize
in a few profitable crops.
Traditionally grown near
markets. Commercial Agriculture:
Plantations today are almost
always in the tropics, and in
less developed countries.
Outside, often absentee
Labor may be imported to an
otherwise uninhabited area.
Crops are grown almost
exclusively for sale in distant
markets – mostly in
Specialization in one or two
crops (for example,
bananas, tea, coffee, oil
palm, teak, sugar, rubber,
tobacco, etc.). With modern transportation,
areas like California's Central
and Imperial Valleys,
Arizona's Gila River Valley,
parts of Texas, Florida,
Georgia, etc. have become
truck farming areas for the
whole country. Source: http://my.dmci.net/~kingcm/kingfamily/02-organicfarming.html 33 Agriculture & the Environment
Agriculture is severely constrained by:
– Sources: http://www.photolib.noaa.gov/coastline/line0419.htm;
http://www.ars.usda.gov/is/AR/archive/oct98/odor1098.htm 32 Climate
Yes, it's possible to grow tomatoes in Iceland or lettuce in
Saudi Arabia – but it's expensive, and takes sophisticated
technology. Sources: http://www.photolib.noaa.gov/coastline/line0419.htm;
http://edcdaac.usgs.gov/glcc/fao/ 34 Soil Salinization
Salinization is the
concentration of salts
naturally in arid areas.
practice — especially
in arid climates — can
turn fertile farms into
a wasteland. Agriculture can have a strong – even devastating –
impact on the natural environment:
– Slash-and-burn agriculture (if poorly done, can ruin forest
lands for years)
– Overgrazing (can cause soil loss, erosion)
– Desertification (agriculture practiced on marginal lands can
degrade land, expanding arid areas)
Severe salinization, San Joaquin Valley
Source: http://www.ars.usda.gov/is/pr/2004/040902.htm?pf=1S 35 36 6 Global Soil Degradation (all sources – salinization, topsoil loss, etc.) Agriculture and Economics:
– A rising population means that
subsistence farmers must produce more
– According to Esther Boserup, this means
that they will use newer, more intensive
forms of agriculture to increase yield.
– Great idea – except that it's not possible
in all areas, due to environmental factors. International trade:
– The idea of talking about "subsistence"
and "trade" seems contradictory – but
many subsistence farmers do produce
– The most popular (and most profitable):
37 Coca production
regions in Peru Source: http://www.usdoj.gov/dea/pubs/intel/01012/01012.html 38 Problems in Commercial Agriculture Agriculture and Economics:
Commercial Agriculture Overproduction – Commercial farmers suffer from low incomes because they
produce too much.
– In developed countries, modern crop varieties, machines,
chemicals, etc. have increased yields enormously - the
greater the supply, the lower the price.
– Most governments in the developed world have instituted
farm subsidy policies to either protect domestic producers or
limit production. In 1826 Johann Heinrich von Thünen
noticed something interesting - identical
physical characteristics (climate, soil)
didn't mean identical crops.
The crops farmers chose to plant were
– Crop value
– Land value
– Cost of transportation Sustainable Agriculture – This includes organic farming as well as various forms of
integrated pest management.
– Various techniques, including ridge tillage, limited use of
pesticides and herbicides, and integration of crops and
animal production. Von Thünen's model did not take into
account any actual site factors - rivers,
roads, etc. - but the model can be
modified to deal with them.
The model is still useful - it helps explain
why farmers choose the crops they do,
where it makes sense to produce lowvalue bulky commodities, and where it
doesn't, etc. Off-farm migration – In many areas of the developed world it has become difficult
to get people to stay in farming regions.
– This leads to greater dependence on migratory labor,
absentee ownership, and consolidation of farms and farming. 39 Problems in Commercial
Agriculture 40 Monoculture
& Disease Loss of crop
– Replacement of
local varieties with
– Loss of unique
– Loss of genetic
resources. By replacing local varieties (“land races”) with
new, improved crops, productivity can be
But the new improved crops may lack
resistance to disease – and since everybody
grows the new crops, everybody’s at risk.
41 Source: http://environment.newscientist.com/channel/earth/mg19425983.700 42 7 Monoculture:
Disaster Increasing Food Supplies Gros Michel banana The bananas that you
eat today are not the
bananas that your
All commercial bananas
are seedless – they
reproduce from “roots.”
In essence – they’re
When disease strikes,
all bananas from the
same clone will be
equally vulnerable. Possible strategies: Cavendish banana Unfortunately, bananas are
susceptible to many diseases –
Panama disease, Black
Sigatoka disease, Banana
Bunchy Top Virus, etc.
When Panama disease wiped
out the commercial crops of
Gros Michel, growers switched
Now that Cavendish is in
trouble, growers are looking for
something new – but they
haven’t found it yet. Sources: http://wwwchem.uwimona.edu.jm:1104/lectures/banana.html; http://en.wikipedia.org/wiki/File:Bananas.jpg –Diet modification
(shift to less harmful food sources).
–Expanding agricultural land.
–Increasing the productivity of
–Identifying & exploiting new food
–Increasing exports. 43 44 Diet Modification
Animals like cows, pigs and sheep consume
far more energy (and resources like water)
than they provide as food. Enormous
amounts of pollution are created in
commercial livestock production.
A shift to vegetable protein sources would
be more efficient and result in less waste.
– Livestock production is frequently the only
agricultural activity that’s possible in many
areas (it’s hard to raise soybeans in a desert).
– Large scale commercial agriculture is also a
significant source of waste and pollution.
http://www.tucsonweekly.com/gbase/Opinion/Content?oid=oid%3A107527 45 Expanding Agricultural Land Sources: http://www.nytimes.com/2008/01/27/weekinreview/27bittman.htm?_r=2&oref=slogin&oref=slogin 46 Arable Land Per Capita Only about 11% of the world’s land is
currently being used for agriculture.
By increasing the area in production, we can
expand the food supply.
– Environmental problems (desertification,
waterlogging) have made some farmland unusable.
– Expanding urban areas frequently take farmland
out of production.
– Most of the earth’s remaining land is not suitable
for agriculture – too hot, too cold, too steep –
without enormous modification and improvement.
47 Source: http://www.unep.org/Geo2000/english/i76a.htm 48 8 New Food Sources Increasing Productivity We get most of our food from a very limited
number of plants and animals – rice, wheat,
corn, sorghum and millet, potatoes, sweet
potatoes, cows, pigs, chickens and sheep.
By expanding our horizons we can gain access
to enormous new resources.
Strategies We have already made enormous
improvements in productivity – better
fertilizers, pesticides, herbicides, farm
machinery – and better plants through the
By continuing to improve technologically
(especially with genetically modified crops),
we can increase food supplies for the
Problems – Ocean farming (aquaculture)
– New high-protein cereals
– Encourage use of underused foods Problems – Hybrid seed, fertilizers, pesticides, farm machinery,
etc. are expensive, and may be impossible for poor
farmers to afford.
– Genetically modified crops are controversial, and
may be unacceptable.
49 Aquaculture: Farming the Seas – Most of the strategies are enormously more difficult
than our current approaches – which is why haven’t
been doing them.
– In many cases they require expensive inputs of
energy and resources, and may require people to
change their way of life.
50 High-Protein Cereals
Golden rice “Green Revolution” rice Eastern gamagrass Sources: http://aquaculture.noaa.gov/; http://www.noaanews.noaa.gov/stories2006/images/aquaculture-hawaii-kona-blue07-2006b.jpg; http://www.lib.noaa.gov/docaqua/reports images/yarish6.jpg 51 New Food Sources 52 Increasing Food Exports
As productivity increases around the
world, countries that once had to
import food can become food
exporters – and the price of food will
Problems Cuphea species for oil Amaranth species for grain, oil, and vegetables – Not all areas can produce surpluses, even
with new crops or techniques.
– Increasing reliance on foreign sources of
food is a potential political problem, as
well as a source of economic uncertainty. Indian Rice Grass flour
Sources: http://www.ars.usda.gov/is/AR/archive/dec99/crop1299.htm; http://businessresources.mt.gov/BRD_RCT_Success.asp;
http://www.ars-grin.gov/ars/MidWest/Ames/repository/oldsitearchive/Crops_New/Amaranth.html Sources: http://usinfo.state.gov/journals/ites/1005/ijee/buell.htm; http://www.ars.usda.gov/is/timeline/green.htm;
http://www.ars.usda.gov/is/timeline/green.htm 53 54 9 Sources: http://www.fao.org/SD/EIdirect/gis/EIgis000.htm; ftp://ftp.fao.org/docrep/fao/009/a0750e/a0750e00.pdf 55 10 ...
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- Fall '10
- Geography, genetically modified crops, commercial agriculture